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3a23fdf359
Includes harmonizing the display of options and arguments, standardising terminology, using the envvar directive more broadly, adding help options to all commands that support them, simplifying some language, and tidying up multiple formatting issues. string documentation is not changed.
56 lines
1.4 KiB
ReStructuredText
56 lines
1.4 KiB
ReStructuredText
.. _cmd-begin:
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begin - start a new block of code
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=================================
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Synopsis
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--------
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.. synopsis::
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begin; [COMMANDS ...]; end
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Description
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-----------
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``begin`` is used to create a new block of code.
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A block allows the introduction of a new :ref:`variable scope <variables-scope>`, redirection of the input or output of a set of commands as a group, or to specify precedence when using the conditional commands like ``and``.
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The block is unconditionally executed. ``begin; ...; end`` is equivalent to ``if true; ...; end``.
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``begin`` does not change the current exit status itself. After the block has completed, ``$status`` will be set to the status returned by the most recent command.
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The **-h** or **--help** option displays help about using this command.
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Example
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-------
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The following code sets a number of variables inside of a block scope. Since the variables are set inside the block and have local scope, they will be automatically deleted when the block ends.
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::
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begin
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set -l PIRATE Yarrr
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...
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end
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echo $PIRATE
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# This will not output anything, since the PIRATE variable
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# went out of scope at the end of the block
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In the following code, all output is redirected to the file out.html.
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::
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begin
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echo $xml_header
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echo $html_header
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if test -e $file
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...
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end
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...
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end > out.html
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